Canadian police said Monday that two suspects arrested Monday for allegedly plotting to derail a passenger train in the greater Toronto area had gotten “direction and guidance” from Al Qaeda elements located in Iran. Police did not provide further evidence of the alleged link at a news conference Monday.

Canadian authorities told reporters there was nothing to indicate the plan was “state-sponsored,” meaning the Iranian government was not believed to be involved. Iran nonetheless bristled at the suggestion that Al Qaeda had been able to plot from its soil.

Al Qaeda "has no possibility to do any activity inside Iran or conduct any operation abroad from Iran's territory,” Alireza Miryousefi, spokesman for the Iranian mission to the United Nations, said in a statement emailed to the Associated Press. “We reject strongly and categorically any connection to this story.”

Iran is largely Shiite, while Al Qaeda is a Sunni extremist organization, and the two have thrown their support behind opposing sides in the bloody conflict in Syria. Tehran has also held members of Al Qaeda who fled Afghanistan under house arrest, closely monitoring their activities.

Other analysts, however, have argued that Iran might be willing to work with Al Qaeda against a shared enemy. In October, the U.S. Treasury Department said Iran has allowed Al Qaeda to operate a pipeline moving money and fighters to support Al Qaeda activities in South Asia.

Angered by Iranian support for Syrian President Bashar Assad and other stands taken by Tehran, Canada closed its embassy in Iran and cut off diplomatic relations in September. At the time, its foreign affairs minister, John Baird, called the Iranian government "the most significant threat to global peace and security in the world today."